/elixir

"it's the future" -mr.robot

Primary LanguageElixir

elixir

"it's the future" -mr.robot

enter: iex
exit : control c control c
run : elixir hello_world.exs

in iex:
- h --> help, list of commands
    ex: h String.downcase

WHY ELIXIR

  • syntax based loosely on ruby, and cherry picked from other languages
  • industrial strength
  • future = everything is networked
  • can handle concurrency
  • is fault tolerant
  • developer friendly, nice tools, has decent error messages
  • highly scalable, highly concurrent, extremely robust in fault tolerant systems,

As a programming paradigm, concurrent computing is a form of modular programming, namely factoring an overall computation into subcomputations that may be executed concurrently.

What do i need to learn:
  • Read, write elixir code
  • Create and write recursive function
  • Structure programs
  • Call erlang code from elixir programs
  • Import elixir and erlang dependencies and use in code
  • Add own configuration into configuration files, and use in program
  • Processes, execute functions within processes, send and receive messages b/w processes
  • Write functional programs and thing functional way, by understanding pattern matching concepts
  • OTP (framework and tools erlang uses to creating distributed and fault tolerant programming
  • Functional programming
  • Interactive mode REPL (read evaluate print loop) {iex}
  • Two types of files
    • .ex → compiled down to byte code and run on the erlang beam
    • .exs → scripting files, interpreted like ruby and python
  • use snake case to name files
    • hello_world.exs
  • comment with #
  • functions are grouped in modules
  • String interpolation

    • iex> name = "sean"

    • iex> "Hello #{name}"

    • iex> name = "Sean"

    • iex> "Hello " <> name

  • Lists can include multiple types

  • It’s faster to prepend instead of appending (time complexity is 0n) b/c similar to linked lists

  • List concatenation == “++”

  • iex> list = [3.15, :pie, "Apple"]

  • iex> [“π”] ++ list

  • iex> [1, 2] ++ [3, 4, 1]

  • iex> ["foo", :bar, 42] -- [42, "bar"] ["foo", :bar]

  • iex> IO.puts("Hello World!")

    • Hello World!
    • :ok

  • IO module

    • :ok is an atom

  • To find details about what functions a module has

    • String.downcase == man
    • String. {tab}
      • Shows all possibility you can put with string module
    • C = compile
      • c "./hello_world.exs"

  • Compile a file in iex

  • To configure iex

    • h IEx.configure

  • Atom

    • A constant

BASIC TYPES

  • Integers → unlimited size, can use _ separator (1_000_000 == 1000000)

  • Octals, hexadecimals, binaries

  • Floating points

  • Exponents

  • 3141.0e6

  • Atoms

  • Immutable strings

    • :hello

  • Used as keys, to reference erlang functions, to reference functions within elixir

  • Strings

    • “” == string
    • ‘’ == sequence of characters
    • Is_list == ‘hello’
    • Use byte_size
    • booleans